"The Treaties shall cease to apply to the State in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the Member State concerned, unanimously decides to extend this period,” he said.

In a referendum held on June 23, nearly 52 percent of British voters, amounting to more than 17 million citizens, opted to leave the EU, a decision that sent shock waves throughout the world.

May has vowed to trigger the negotiations by the end of March, starting two years of talks with the EU over the terms of the country’s exit. The lawyer, however, said Britain can simply leave the EU without a withdrawal agreement two years after it issues a leave notice.

"If Britain had issued the Article 50 Notice immediately after the Brexit referendum, Britain would have eaten 7 months of the 24 month countdown clock, and pressure would be mounting on the EU to agree a fair exit deal with Britain,” he added.

He explained that the Lisbon Treaty does not impose any financial penalties on Britain if it leaves the union without agreement.

British lawmakers overwhelmingly backed a bill on Wednesday, enabling May to officially start negotiations for leaving the EU. She will deliver a letter to the European council on 9 March to trigger Brexit.